Engine starter



W. L. MCGRATH ENGINE STARTER Aug. 2, 1927.

original Filed A1122, 1919.

2 Sheets-Sheet l.

@Ei/M5 772%?165565 Mm www MMM W. L. MCGRATH ENGINE STARTER Aug. 2, 1927.

Original Filed Aug. 2, 1919 2 Sheets-Sheet 2 l .Inf/@MOP MMM] Patented Aug. v2, 1927.

l l N1,631,422 1 y UNITED sTATEsPAjrl-:NT OFFICE.

WILLIAM L. MGGEATH, or ELMIRA, NEW Yonx, AssrefNon' 'ro ECLIPSE MACHINE con` PANY, or unirme. NEW You',

ENGINE Application ledAugust 2, 1919, Serial My invention relates toy engine starters and concerns the drive or -transmission for transrnitting the power vof the primemover or source of power to the member of the engine to be started. In the present instance 'my invention is shown embodied in a drive of the Eclipse-Bendix type and will be described in connection therewith.

In the type of drive shown a driving member or pinion' is mounted on a rotatable mem# .ber or screw shaft in such manner as to move longitudinally thereof and, rotarily therewith wherebysuch driving member or pinion is automatically advanced into engagement with the engine member such as the flywheelV of the engine and thereupon partakes of rotary movement of the screw shaft-to thereby rotate the flywheel and start the engine.

In the usual form of Eclipse-Bendix drive this screw shaft is operatively connected with av driving shaft such as the 'extended armature shaft of an electric motor or a countershaft driven thereby, by means of a coiled driving spring. In the event of the -abutting of the pinion teeth against the flywheel teeth end to end the screw, shaft will continue to rotate while the pinion' is stopped in its longitudinal movement, until such time as the pinion is caused to rotate slightl so as to bringabout register between sail teeth, whereupon full mesh is obtained.

According to my invention provision isl made whereby thescrew shaft is normally in driving relationship withethe spring driving connection and the driving shaft but is permitted to become disengaged from such driving relationship whenever the said abutment of the pinion teeth' and flywheel teethl occurs. `According to my present invention the screw shaft will become disengaged under such condition and the pinion will be withdrawn from the flywheel andthe starting operation will be repeated automatically until proper mesh between the pinion and the In the drawings,` Fig. l is a sectional elevation of a starter embodying my invention; Figs. 2 and 3 sections on the lines 2-2 and 3 3 respectively ofl Fig. l; and Fig. 4 a view similar to Fig. -1 but showing certain of the parts under the condition of abutment of the pinionteeth and iiywheel teeth end to end.

For the purpose of a clear and definite A conPonA'rIoN or NEW Yoax. STARTER n No. 314,951. :renewed January 19, 1927.

stood that my invention in its broader as ectl is not limited to this particular t e. oreover while I have yp shown my invention in connection with a drive of the so-called single reduction type, that is, where the driving shaft is directly driven by the motor and is as usual the extended armature shaft of the motor, my invention lis not limited thereto, but is equally applicable to a drive ofthe double reduction type in which such driving shaft is indirectly driven by the motor.

As shown the motor 1 has a driving shaft 2 which is here the extended armature shaft thereof, provided` with a suitable bearing 3 at' its outerend. To the inner end of this shaft there is secured -by the stud 4 a driving head 5. Another driving head 6 is also mounted on the shaft but is free to float thereon. These two driving heads are operatively connected by means of the coiled driving spring 7, one end of which is secured to the stud 4 and the other end to the stud 8. i

l Upon the driving shaft 2 is mounted a hollow screw shaft 9 upon which is screw threaded the driving member or 'pinion 10, the latter being adapted to mesh with the teeth 11 of the engine member such as the flywheel 12. This screw shaft is operatively connected under normal conditions with the driving head 6 for driving the engine member and when rotated thereby the pinion will automatically advance inwardly into mesh 'Y with the flywheel teeth and as full mesh is obtained it will rotate with the screw shaft.

Thereafter when the engine starts on its own power such pinion will be automatically demeshed.

The driving head 6 and screw shaft 9 are not operatively connected permanently but are operatively connected onl under normal conditions. As shown they iave clutch en? is made against the tension of a light coil spring 16 which encircles the outer end of the screw shaft and has one end 17 secured to the weight portion 18 of the weighted disk e of the pinion, and its other end 19 secured by means of the screw 2O to the sleeve 21 which is secured to the outer end of the screw shaft. When the pinion moves inwardly towards the iywheel this coil spring will become extended and wound up as shown in Fig. 4 it being understood that such spring is so light that it will not interfere with this advancmg longitudinal movement of the pinion when the screw shaft is positively rotated for the starting operation. e

Under normal conditions-the driving head 6 and the screw shaft are operatively connected by means of the clutch and such connection remains whenever proper register occurs between the pinion teeth and the iiywheel teeth. If, however, thev teeth 10 of the pinion abut the iiywheel teeth 11 end to end, the pinion is stopped in its longitudinal movement with reference to the screw shaft, and as the clutch jaws .1S- 14 are in engage.- ment, the screw shaft will continue to rotate, thereby carrying the screw shaft to the left against the pressure of the spring 22 until the clutch jaws 13-14 are out of engagement. The pressure of the pinion against the flywheel at this time will be comparatively llight. The torsion spring 16 being now wound up toan appreciable extent, its tendency will be either to rotate the screw shaft within the pinion,carrying said screw shaft to the right, or to rotate the pinion on the screw shaft, carrying said pinion to the left. It is conceivable that owing to the fric-v tion of the screw shaft with shaft 2, and the fact that the pinion has manifestly abutted .the teeth with comparatively slight pressure,

that the pinion may rotate on the screw shaft first, thereby returning to normal or home positionv thereon, and at substantially the same time the spring 22 will urge the screw shaft toward the right until the clutch jaws 13 and 14 contact in whichever position they happen. to align at the moment, unless the pinion teeth again contact the iywheel teeth before the clutch jaws 13-14 contact, in

which latter case the described operation will be repeated. In case the spring 16` should turn the pinionslightly so as to occasion register between` the teeth and the should then `act instantly before e spring 16 has been able to withdraw the pinion to home position, such teeth will mesh and the clutch rjaws will be ite-connected for driving purposes. However, should friction conditions be such that ktendency is to urge `the screw shaft tc the right, the spring 16 causing it to rotate' in the pinion, the longitudinal movement of the screw shaft will be similarlystopped on contact of the clutch jaws 13 and let longitudinally, and the remainder of the tension of the spring 16 will retract the pinion from contact with the iiywheel teeth.

It will thus be seen that regardless of the exact sequence of operations or of varying frictional conditions present, the desired function of the structure as shown is accom plished.

Thus the device will operate automatically without damage or injury to the parts untllg a pinion adapted to mesh directly with the engine member but it will be understood that this invention'is not limited directly to this type of driving member and also that such invention may be incorporated in that type of drive in which the member screw threaded on the screw shaft is a control member which controls the actual driving member that engages directly with the engine member. Moreover it will be understood that the drive spring while :of the samegeneral character as that in use in the Eclipse-Bendix drive must in this instance be wound opposite to the direction of the thread of the screw shaft. For instance, in the present case, a right hand spring is employed with a left hand thread on the screw shaft. Furthermore, damage to the parts is prevented in case of any extraneous obstruction to the travel of the pinion, as might occur from a loose bolt in the adjacent housing or supporting parts.

. I claim:

1 ,The combination of a driving element, a rotatable shaft, a driving member mounted on thc shaft for longitudinal movement thereof and rotary movement therewith, and means which normally connect said element and Shaft together for transmitting vthe torque for the driving operation but adapted to be operated to disconnect them when the longitudinal movement of the driving member is interrupt-ed. v

2. The combination of a driving element, a rotatable shaft, ak driving member mounted on the shaft for :longitudinal movement thereof and rotary movement therewith, and a clutch which normally connects said element and shaft together for transmitting the torque for the driving operation but adapted to be' released when the longitudinal movement of the driving member is interrupted.

The driving member is in the present case l lconnection of the element and shaft being 4. The combination of a driving element,

a rotatable shaft, a driving member mounted on the shaft for longitudinal movementv thereof and rotary movement therewith, and means which normally connectsaid element and shaft together for transmittin the torque for the driving operation but a apted to be operated to disconnect them, said disunder the control of the driving member in ,its longitudinal movement.

5. The combination of a driving element, a rotatable shaft, a driving member mounted on the shaft for longitudinal movement thereof and rotary movement therewith, and a clutch which normally connects said element and shaft together for transmitting the torque for the driving operation and the release of which is yunder, the` control of the driving member in vits longltudinal movement.

6. The combination of a driving element, a rotatable shaft, a driving member `mounted on the shaft for longitudinal movement thereof and rotary movement therewith, means which normally connect said element and shaft together for transmitting the torque for the driving operation but adapted to be operated to disconnect them, and resilient means for returning the driving nember to normal position 'on the shaft.

7. The combination of a driving element, a rotatable sh ft, a driving member mountedton the sha'1 t for longitudinal movement thereofand means which normally connect said element and shaft together for transmitting the torque for the driving operation but adapted to be operated to disconnect them, and a spring connected with the shaft and driving member for returning the latter to normal position on the shaft.

8. The combination of a driving element, a rotatable'shaft, a driving member mounted on the shaft for longitudinal movement thereof and rotary movement therewith, means which normally connect said element and shaft together 'for transmitting the torque for the driving operation but adapted to be operated to disconnect them, and yielding means for normally maintaining said driving connection through said connecting means but adapted to yield to permit the release thereof.

I 9. The combination of a driving element,

'rotary movement therewith,f

a rotatable shaft, a driving member mounted on the shaft for longitudinal movement thereof and rotary' movement therewith, means which normally connect said element and shaft together for transmitting the torque for the driving operation but adapted to be operated to disconnect them, and a spring for normally maintaining said driving connection through said connecting means but adapted to yield to permit the release thereof.v

l0. The combination of a driving element, a rotatable shaft, 'a driving member mounted on the shaft forlongitudinal movement thereof and rotary movement therewith, means which normally connect said element and shaft vtogether for transmitting the torque for the drivin operation but adapted to be operated to disconnect them, means lfork normally maintaining said driving connection through said connecting means but adapted to yield to permit the release thereof, and resilient means for returning the driving member to normal position on the shaft.

11. The combination of a driving element, a rotatable shaft, a driving member mounted on the shaft for longitudinal movement thereof and rotary movement therewith, means which normally connect said element and shaft together for transmitting the torque for the driving operation but adapted to be operated to disconnect them, a spring acting on the shaft for normally maintaining said driving connection through said connecting means but adapted to yield to permit the release thereof, and a spring connected with the shaft and driving member for returning the latter to normal position on the shaft.

12. The combination of a driving element, a rotatable screw-shaft, a driving member threadedv thereon for longitudinal movement thereof and rotary movement therewith, a clutch normally connecting said element and shaft for transmittin the torque for the driving operation, a spring for normally holding the clutch in operative condition but adapted to yield to release such clutch, and a spring connected with the `shaft and driving member for returning the latter to normal position on the shaft.

13. The combination of a driving element, a rotatable screw-shaft, a. driving member threaded thereon for longitudinal movement thereof and rotary movement therewith, a clutch normally connecting said element and shaft for transmitting the torque for the driving operation, a spring for normally holding the clutch in operative -condition but adapted to yield to release such clutch. and a spring connected with the shaft and driving member for returning the latter to norrnai position on the shaft, said screwshaft being mounted to move longitudinally against the tension of the first-named spring when the longitudinal movement of the driving-member is interrupted.

14. The combination of a driving element,

- ment of the driving member is interrupted.

, 15.A 'lhe combination of a driving element, a rotatable shaft, said element and shaft being arranged coaxially and having at their adjacent ends complementary clutch jaws -v which are normally engaged to transmit all the torque for the driving operation, and a driving member mounted on the shaft for longitudinal movement thereof and rotary movement therewith, said clutch jaws being adapted to be disconnected when the longitudinal movement of the driving member is interrupted.

16. The combination of a yieldingly driven driving head, a rotatable shaft normally operativly connected with said head for transmittin the torque for the driving operation but a apted to be disconnected therefrom upon relative longitudinal movement of said head and shaft one with'respect-to the other, and a driving member mounted on the shaft for longitudinal movement thereof and rotary movement therewith.

17. The combination of a driving element, a rotatable shaft, said element and shaft being arranged co-aXially and being normall operativel engaged for driving but one being mova le axially for disengagement, and a driving member mounted or. t e shaft for longitudinal movement thereof and rotary movement therewith.

18. rlhe combination of a rotatable driving element having a clutch member, arotatable screw shaft having at one end a stop means and terminating in a corresponding clutch member, which clutch members are normally engaged, and a driving member screw threaded on the shaft for longitudinal movement thereof and rotary movement therewith when in contact with said stop means, said shaft being mounted to slide longitudinally to disengage said members when said longitudinal movement of the driving member is interrupted.

19. The combination of a rotatable driv ing shaft, a driving element mounted to float thereon, a yielding driving connection between it and the shaft, a rotatable driven shaft normally operatively connected with Y such element but adapted to be disconnected therefrom and a. driving member mounted on the shaft forlongitudinal movement thereof and rotary movement therewith.

20. The combination of a rotatable driving shaft, a driving element mounted to loat thereon, a yielding driving connection between it and the shaft, a rotatable driven thereon, a yielding'driving connection be-` tween it and the shaft, a rotatable driven shaft normally operatively connected with such element but adapted to be disconnected therefrom, said driven shaft being a` hollow screw shaft mounted on the drivin shaft, and a driving member screw threaded on the screw shaft for longitudinal movement thereof and rotary movement therewith.

22. The combination of a rotatable driving shaft, a .drivinghead in the form of a sleeve loosely mounted thereon and having clutch jaws at one end, a yielding driving connection between the-shaft and head, a hollow screw shaft mounted on the driving shaft and having a longitudinal movement thereon, said screw shaft having at one end clutch j awsn-ormally in engagement with the other clutch jaws, and a driving member screw threaded on the screw shaft for longitudinal movement thereof and rotary movement therewith.

23. The combination of a driving element,

a rotatable shaft, a driving member mounted on the shaft for longitudinal movement thereof and rotary movement therewith, and means which normally connect said element and shaft together for transmitting the torque for the driving o eration but adapted to be operated to isconnect them by relative longitudinal movement of such elenect said element and shaft together for transmitting the torque for the driving oper- 'ation but adapted to be operated to disconnect them when said shaft is moved longiltudinally.

WILLIAM L. MCGRATH.

'ment and shaft oneA with respect to the j 

